Snakes Alive!

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Snakes Alive!

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The story

Remember, remember the 5th of November…

But does anyone remember the indoor fireworks that were so popular when I was growing up?

I suspect not as the exciting images and amazing claims on the packaging did not exactly match the reality.
For example: ‘Puff the magic dragon – Puff comes to life and he’s furious! Smoking nostrils of terror, watch out!’ is in fact two sticks which bear a resemblance to cigarettes that gently smoke when lit. Let’s be honest, they were not exactly awe-inspiring. In fact, the only one I can remember with fondness is the magic snake.

The great news is, this can be carried out in the science lab with a few chemicals from the store-cupboard.  Instructions on how to do so can be found from the weblink below.

Teaching ideas

This demonstration utilises a few different chemical reactions.

You could show this to a KS3 class and ask them to decide whether this is showing a chemical reaction or a physical change and what evidence they have (colour change, gas produced, heat produced, irreversible etc). KS4 students could go further and explain how the firework works.

I have provided a resource for this.

Students are given a set of cards made from the second PowerPoint slide and have to use them to write an explanation with word equations as to how the firework works. You could challenge the more able to include symbol equations as well.

For your information, the snake appears because burning the propanol (isopropyl alcohol) provides heat. This breaks up the sodium hydrogencarbonate, releasing carbon dioxide. The heat also caramelises the sugar, making it turn black. The snakes grow because of the pressure from the carbon dioxide being released.

From researching this firework, I discovered that it is one of the few fireworks that you are allowed to buy in the US state of Iowa where the public sale and use of fireworks is banned. This could be the basis of an interesting debate: should fireworks be banned in the UK? Students could be split into teams, research the facts and then present the debate.

I hope you and your students have a fun, and safe, Bonfire Night.


Instructions for the snake firework

Should fireworks be banned in the UK? News article to start this debate

Ideas for other firework based science lessons

My post and lesson idea from last year’s Bonfire Night